Fan

ABSTRACT

The present invention is to provide a fan, comprising a base and a nozzle mounted on the base. The nozzle has a first wall, a second wall arranged generally parallel to the first wall, and a partition wall located between the first wall and the second wall. The partition wall split the airflow outlet of the base to a first nozzle airflow outlet and a second nozzle airflow outlet. The first wall edge of the second wall is folded in an annularly curved or bent manner to form a first Coanda surface adjacent to the first nozzle airflow outlet and capable of producing the Coanda effect, and the partition wall is folded either inward in an opposite direction of an airflow direction or outward in the airflow direction in an annularly curved or bent manner to form a closed wall, the closed wall forming a second Coanda surface adjacent to the second nozzle airflow outlet and capable of producing the Coanda effect.

BACKGROUND OF THE INVENTION Technical Field

The present invention relates to a fan and more particularly to onetaking advantage of the Coanda effect to increase the overall flow rateof its output airflow.

Description of Related Art

Fans typically have blades or vanes, which nevertheless hinder passageof light, are difficult to clean, compromise the portability of fans,and take up considerable space when the fans are used in vehicles.

A bladeless fan is disclosed in U.S. Pat. No. 2,488,467. Lacking aCoanda surface, however, this bladeless fan does not produce the Coandaeffect, meaning the fan cannot entrain an airflow from the surroundingsto increase the overall flow rate of the output airflow. In addition,known bladeless fans do not have a diffusion surface for guiding anairflow in a predetermined direction and therefore fail to guide an aircurrent effectively.

As to bladeless fans with a Coanda surface, it is generally required toincrease the volume of the nozzle if it is desired to enlarge the Coandasurface without increasing the nozzle openings. This has been a problemto be solved in the fan industry.

BRIEF SUMMARY OF THE INVENTION

The objective of the present invention is to solve the aforesaid problemthat, in order to enlarge the Coanda surface of a conventional bladelessfan without increasing the nozzle openings, the nozzle of the fan mustbe increased in volume.

To achieve the objective, the present invention provide a fan,comprising: a base; and a nozzle mounted on the base and having: anozzle airflow inlet located at the nozzle and configured as an openingfor receiving an airflow ejected from the base; a first wall; a secondwall arranged generally parallel to the first wall; a first wall endlocated at an end of the generally parallelly arranged first and secondwalls; a second wall end located at an opposite end of the generallyparallelly arranged first and second walls; first wall edges, which arewall edges of the generally parallelly arranged first and second wallsthat jointly extend to a side; second wall edges, which are wall edgesof the generally parallelly arranged first and second walls that jointlyextend to an opposite side; a partition wall located between the firstwall and the second wall; a first nozzle airflow outlet located betweenthe first wall edge of the second wall and the partition wall andconfigured as an opening for ejecting an airflow; and a second nozzleairflow outlet located between the first wall edge of the first wall andthe partition wall and configured as an opening for ejecting an airflow;wherein the first wall edge of the second wall is folded in an annularlycurved or bent manner to form a first Coanda surface adjacent to thefirst nozzle airflow outlet and capable of producing the Coanda effect,and the partition wall is folded either inward in an opposite directionof an airflow direction or outward in the airflow direction in anannularly curved or bent manner to form a closed wall, the closed wallforming a second Coanda surface adjacent to the second nozzle airflowoutlet and capable of producing the Coanda effect.

Further, the second wall edges form a closed side for preventing anoutgoing airflow or an opening that allows passage of an airflow.

Further, the second wall is folded inward in the opposite direction ofthe airflow direction in an annularly curved or bent manner to form aclosed wall for preventing an ingoing airflow, or the second wall isfolded outward in the airflow direction in an annularly curved or bentmanner to form the first Coanda surface adjacent to the first nozzleairflow outlet and capable of producing the Coanda effect.

Further, the second wall end is joined with the first wall end to forman annular hollow portion, and the annular hollow portion encircles acentral hollow portion that allows passage of light and an airflow.

Further, the second wall end has a second tightly closing wall forpreventing passage of an airflow, and the first wall end has a firsttightly closing wall for preventing passage of an airflow.

Further, there is one said nozzle airflow inlet, provided at the firstwall or the second wall; or there are a plurality of said nozzle airflowinlets, provided at the first wall or the second wall.

Further, the second nozzle airflow outlet formed between the first walledge of the first wall and the partition wall is a tapered slit, and thefirst nozzle airflow outlet formed between the first wall edge of thesecond wall and the partition wall is a tapered slit.

Further, the second nozzle airflow outlet formed between the first walledge of the first wall and the partition wall is a rectangular slit, andthe first nozzle airflow outlet formed between the first wall edge ofthe second wall and the partition wall is a rectangular slit.

Further, the first nozzle airflow outlet or the second nozzle airflowoutlet is divided into a plurality of spaces by a plurality of partitionplates.

Further, there are a plurality of said partition walls so as to form aplurality of said second Coanda surfaces as well as a plurality of saidsecond nozzle airflow outlets.

Further, the second wall has a diffusion surface for guiding an airflowin a predetermined direction.

Further, the second wall edge of the first wall is folded in anannularly curved or bent manner to form a third tightly closing wall,and the third tightly closing wall is adhesively attached to the secondwall to prevent an outgoing airflow.

Further, the second wall edge of the second wall is folded in anannularly curved or bent manner to form a third tightly closing wall,and the third tightly closing wall is adhesively attached to the firstwall to prevent an outgoing airflow.

Further, the nozzle includes a third tightly closing wall, and the thirdtightly closing wall has two sides adhesively attached to the first walland the second wall respectively to prevent an outgoing airflow.

Further, the base has an internal fan for taking in air and ejecting anairflow, a base airflow inlet for taking in air, and a base airflowoutlet for ejecting an airflow.

Further, the internal fan is a forced-draft fan, a planar fan, or a jetturbine-blade fan.

Further, the internal fan is a plurality of parallel-connected orseries-connected planar fans.

Further, the base comprises a filter screen provided therein.

The present invention solves the problem that the Coanda surface of aconventional bladeless fan cannot be enlarged without increasing thevolume of the nozzle, if the areas of the nozzle openings are to remainunchanged.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a partial schematic view of the first example of a nozzlein the present invention.

FIG. 2 shows a partial schematic view of the second example of thenozzle in the present invention.

FIG. 3 shows a front schematic view of the first embodiment.

FIG. 4 shows a sectional schematic view of the first embodiment.

FIG. 5 shows an exploded schematic view of the second embodiment.

FIG. 6 shows a sectional schematic view of the second embodiment.

FIG. 7 shows an external perspective view of the third embodiment.

FIG. 8 shows a sectional schematic view of the third embodiment.

FIG. 9 shows an external perspective view of the forth embodiment.

FIG. 10 shows a sectional schematic view of the forth embodiment.

FIG. 11 shows a schematic view of an example of a forced-draft fan inthe present invention.

FIG. 12 shows a schematic view of an example of a planar fan in thepresent invention.

FIG. 13 shows a schematic view of an example of a jet-turbine fan in thepresent invention.

DETAILED DESCRIPTION OF THE EMBODIMENT OF THE INVENTION

The nozzle referred to in the present invention is described below withreference to two different embodiments.

Please refer to FIG. 1 for a partial schematic view of the first exampleof the nozzle in the present invention.

As shown in FIG. 1, the nozzle 12, to be mounted on a base to increasethe range of airflow input, has a nozzle airflow inlet 121, a first wall122, a second wall 123, a first wall end 124, a second wall end 125,first wall edges 126, second wall edges 127, a first nozzle airflowoutlet 128 a, a second nozzle airflow outlet 128 b, a diffusion surface129, a third tightly closing wall 133, and a partition wall 130.

Located at the nozzle 12, the nozzle airflow inlet 121 is an opening forreceiving the airflow ejected from the base. There may be a singlenozzle airflow inlet 121 provided at the first wall 122 or the secondwall 123. There may alternatively be a plurality of nozzle airflowinlets 121 provided at the first wall 122 or the second wall 123. Thesecond wall 123 is arranged generally parallel to the first wall 122.The first wall end 124 is located at one end of the generally parallellyarranged first and second walls 122 and 123. The second wall end 125 islocated at the opposite end of the generally parallelly arranged firstand second walls 122 and 123. The first wall edges 126 are wall edges ofthe generally parallelly arranged first and second walls 122 and 123that jointly extend to one side. The second wall edges 127 are walledges of the generally parallelly arranged first and second walls 122and 123 that jointly extend to the opposite side. In this embodiment,the second wall edges 127 form a closed side for preventing an outgoingairflow. In another preferred embodiment, the second wall edge 127 ofthe first wall 122 is folded in an annularly curved or bent manner toform a third tightly closing wall 133, and the third tightly closingwall 133 is adhesively attached to the second wall 123 to prevent anoutgoing airflow. In yet another preferred embodiment, the second walledge 127 of the second wall 123 is folded in an annularly curved or bentmanner to form a third tightly closing wall 133, and this third tightlyclosing wall 133 is adhesively attached to the first wall 122 to preventan outgoing airflow. In still another preferred embodiment, the nozzle12 includes a third tightly closing wall 133 with two opposite sidesadhesively attached to the first wall 122 and the second wall 123respectively to prevent an outgoing airflow. The partition wall 130 liesbetween the first wall 122 and the second wall 123. The first nozzleairflow outlet 128 a is located between the first wall edge 126 of thesecond wall 123 and the partition wall 130 and is a tapered opening, ortapered slit, configured for ejecting an airflow. In another preferredembodiment, the first nozzle airflow outlet 128 a is a rectangularopening, or rectangular slit, instead. The second nozzle airflow outlet128 b is located between the first wall edge 126 of the first wall 122and the partition wall 130 and is a tapered opening, or tapered slit,configured for ejecting an airflow. In another preferred embodiment, thesecond nozzle airflow outlet 128 b is a rectangular opening, orrectangular slit, instead. The diffusion surface 129 is formed by thesecond wall 123 and is configured for guiding an airflow in apredetermined direction.

The first wall edge 126 of the second wall 123 is folded in an annularlycurved or bent manner to form a first Coanda surface 134 a adjacent tothe first nozzle airflow outlet 128 a. The first Coanda surface 134 anot only can produce the Coanda effect to increase the overall flow rateof the output airflow, but also helps reduce the overall volume of thenozzle. The partition wall 130 is folded inward (i.e., in the oppositedirection of the airflow direction) in an annularly curved or bentmanner to form a closed wall for preventing an ingoing airflow, whereinthe closed wall forms a second Coanda surface 134 b adjacent to thesecond nozzle airflow outlet 128 b and capable of producing the Coandaeffect to increase the overall flow rate of the output airflow. Thus,without having to change the areas of the nozzle openings or the volumeof the nozzle, the Coanda surfaces can be enlarged to enhance the Coandaeffect and thereby raise the overall flow rate of the output airflow. Inanother preferred embodiment, the partition wall 130 is folded outward(i.e., in the same direction as the airflow direction) in an annularlycurved or bent manner to form the second Coanda surface 134 b.

Please refer to FIG. 2 for a partial schematic view of the secondexample of the nozzle in the present invention.

As shown in FIG. 2, the nozzle 22, to be mounted on a base to increasethe range of airflow input, has a nozzle airflow inlet 221, a first wall222, a second wall 223, a first wall end 224, a second wall end 225,first wall edges 226, second wall edges 227, a first nozzle airflowoutlet 228 a, a second nozzle airflow outlet 228 b, a diffusion surface229, a third tightly closing wall 233, and a partition wall 230.

Located at the nozzle 22, the nozzle airflow inlet 221 is an opening forreceiving the airflow ejected from the base. The second wall 223 isarranged generally parallel to the first wall 222. The first wall end224 is located at one end of the generally parallelly arranged first andsecond walls 222 and 223. The second wall end 225 is located at theopposite end of the generally parallelly arranged first and second walls222 and 223. The first wall edges 226 are wall edges of the generallyparallelly arranged first and second walls 222 and 223 that jointlyextend to one side. The second wall edges 227 are wall edges of thegenerally parallelly arranged first and second walls 222 and 223 thatjointly extend to the opposite side. The second wall edges 227 form aclosed side for preventing an outgoing airflow. The partition wall 230lies between the first wall 222 and the second wall 223. The firstnozzle airflow outlet 228 a is located between the first wall edge 226of the second wall 223 and the partition wall 230 and is a taperedopening, or tapered slit, configured for ejecting an airflow. The secondnozzle airflow outlet 228 b is located between the first wall edge 226of the first wall 222 and the partition wall 230 and is a taperedopening, or tapered slit, configured for ejecting an airflow. Thediffusion surface 229 is formed by the second wall 223 and is configuredfor guiding an airflow in a predetermined direction.

The first wall edge 226 of the second wall 223 is folded inward (i.e.,in the opposite direction of the airflow direction) in an annularlycurved or bent manner to form a closed wall for preventing an ingoingairflow, wherein the closed wall forms a first Coanda surface 234 aadjacent to the first nozzle airflow outlet 228 a. The first Coandasurface 234 a not only can produce the Coanda effect to increase theoverall flow rate of the output airflow, but also helps reduce theoverall volume of the nozzle. In another preferred embodiment, thesecond wall 223 is folded outward (i.e., in the airflow direction) in anannularly curved or bent manner to form the first Coanda surface (notshown). The partition wall 230 is folded inward (i.e., in the oppositedirection of the airflow direction) in an annularly curved or bentmanner to form a closed wall for preventing an ingoing airflow, whereinthe closed wall forms a second Coanda surface 234 b adjacent to thesecond nozzle airflow outlet 228 b and capable of producing the Coandaeffect to increase the overall flow rate of the output airflow. Thus,without having to change the areas of the nozzle openings or the volumeof the nozzle, the Coanda surfaces can be enlarged to enhance the Coandaeffect and thereby raise the overall flow rate of the output airflow. Inanother preferred embodiment, the partition wall 230 is folded outward(i.e., in the airflow direction) in an annularly curved or bent mannerto form a closed wall with the second Coanda surface (not shown).

Please refer to FIG. 3 and FIG. 4 for a front view and a sectional viewof the first embodiment of the present invention respectively.

As shown in FIG. 3 and FIG. 4, the fan 30 in the first embodiment of thepresent invention includes a base 31 and a nozzle 32.

The base 31 has: an internal fan 311 for taking in air and ejecting anairflow, a base airflow inlet 312 for taking in air, and a base airflowoutlet 313 for ejecting an airflow.

The nozzle 32 is mounted on the base 31. Most of the central portion ofthe nozzle 32 is hollow to allow passage of light and an airflow and toincrease the range of airflow input. The nozzle 32 has: a nozzle airflowinlet 321, which is an opening located at the nozzle 32 and configuredfor receiving the airflow ejected from the base airflow outlet 313; afirst wall 322; a second wall 323 arranged generally parallel to thefirst wall 322, wherein in this embodiment, a second wall end is joinedwith a first wall end to form an annular hollow portion that encirclesthe light- and airflow-penetrable central hollow portion of the nozzle;first wall edges 326, which are wall edges of the generally parallellyarranged first and second walls 322 and 323 that jointly extend to oneside; second wall edges 327, which are wall edges of the generallyparallelly arranged first and second walls 322 and 323 that jointlyextend to the opposite side, wherein the second wall edges 327 form aclosed side for preventing an outgoing airflow; a partition wall 330lying between the first wall 322 and the second wall 323; a first nozzleairflow outlet 328 a located between the first wall edge 326 of thesecond wall 323 and the partition wall 330; a second nozzle airflowoutlet 328 b located between the first wall edge 326 of the first wall322 and the partition wall 330, wherein in a preferred embodiment, thefirst nozzle airflow outlet 328 a or the second nozzle airflow outlet328 b is divided by a plurality of partition plates 335 into a pluralityof spaces, and the partition wall 330 is supported by the partitionplates 335; and a diffusion surface 329 for guiding an airflow in apredetermined direction. The first wall edge 326 of the second wall 323is folded in an annularly curved or bent manner to form a first Coandasurface 334 a adjacent to the first nozzle airflow outlet 328 a andcapable of producing the Coanda effect to increase the overall flow rateof the output airflow. The partition wall 330 between the first wall 322and the second wall 323 is folded either inward (i.e., in the oppositedirection of the airflow direction) or outward (i.e., in the airflowdirection) in an annularly curved or bent manner to form a closed wall,wherein the closed wall forms a second Coanda surface 334 b adjacent tothe second nozzle airflow outlet 328 b and capable of producing theCoanda effect. The diffusion surface 329 guides the output airflow inthe predetermined direction.

Please refer to FIG. 5 and FIG. 6 for an exploded schematic view and asectional view of the second embodiment of the present inventionrespectively.

As shown in FIG. 5 and FIG. 6, the fan 40 in the second embodiment ofthe present invention includes a base 41 and a nozzle 42.

The base 41 has: an internal fan 411 for taking in air and ejecting anairflow, a base airflow inlet 412 for taking in air, and a base airflowoutlet 413 for ejecting an airflow.

The nozzle 42 is mounted on the base 41. Most of the central portion ofthe nozzle 42 is hollow to allow passage of light and an airflow and toincrease the range of airflow input. The nozzle 42 has: a nozzle airflowinlet 421, which is an opening located at the nozzle 42 and configuredfor receiving the airflow ejected from the base airflow outlet 413; afirst wall 422; a second wall 423 arranged generally parallel to thefirst wall 422; a first wall end 424 located at one end of the generallyparallelly arranged first and second walls 422 and 423; a second wallend 425 located at the opposite end of the generally parallelly arrangedfirst and second walls 422 and 423, wherein in this embodiment, thesecond wall end 425 has a second tightly closing wall 4251 forpreventing passage of an airflow, and the first wall end 424 has a firsttightly closing wall 4241 for preventing passage of an airflow; firstwall edges 426, which are wall edges of the generally parallellyarranged first and second walls 422 and 423 that jointly extend to oneside; second wall edges 427, which are wall edges of the generallyparallelly arranged first and second walls 422 and 423 that jointlyextend to the opposite side, wherein in this embodiment, the second walledges 427 form an opening through which an airflow can pass; a partitionwall 430 lying between the first wall 422 and the second wall 423; afirst nozzle airflow outlet 428 a located between the first wall edge426 of the second wall 423 and the partition wall 430; a second nozzleairflow outlet 428 b located between the first wall edge 426 of thefirst wall 422 and the partition wall 430; and a diffusion surface 429for guiding an airflow in a predetermined direction. The first wall edge426 of the second wall 423 is folded in an annularly curved or bentmanner to form a first Coanda surface 434 a adjacent to the first nozzleairflow outlet 428 a and capable of producing the Coanda effect toincrease the overall flow rate of the output airflow. The partition wall430 between the first wall 422 and the second wall 423 is folded eitherinward (i.e., in the opposite direction of the airflow direction) oroutward (i.e., in the airflow direction) in an annularly curved or bentmanner to form a closed wall, wherein the closed wall forms a secondCoanda surface 434 b adjacent to the second nozzle airflow outlet 428 band capable of producing the Coanda effect. The diffusion surface 429guides the output airflow in the predetermined direction.

Please refer to FIG. 7 and FIG. 8 for an external perspective view and asectional view of the third embodiment of the present inventionrespectively.

As shown in FIG. 7 and FIG. 8, the fan 50 in the third embodiment of thepresent invention includes a base 51 and a nozzle 52.

The base 51 has: a plurality of internal fans 511 for taking in air andejecting airflows, wherein the internal fans 511 are planar fansconnected in parallel to each other; a base airflow inlet 512 for takingin air; a base airflow outlet 513 for ejecting an airflow; and a filterscreen 514 provided in the base 51 to filter the air flowing into thebase through the base airflow inlet 512.

Mounted on the base 51 to increase the range of airflow input, thenozzle 52 has: a nozzle airflow inlet 521, which is an opening locatedat the nozzle 52 and configured for receiving the airflow ejected fromthe base airflow outlet 513; a first wall 522; a second wall 523arranged generally parallel to the first wall 522; a first wall end 524located at one end of the generally parallelly arranged first and secondwalls 522 and 523; a second wall end 525 located at the opposite end ofthe generally parallelly arranged first and second walls 522 and 523,wherein in this embodiment, the second wall end 525 has a second tightlyclosing wall (not shown) for preventing passage of an airflow, and thefirst wall end 524 has a first tightly closing wall 5241 for preventingpassage of an airflow; first wall edges 526, which are wall edges of thegenerally parallelly arranged first and second walls 522 and 523 thatjointly extend to one side; second wall edges 527, which are wall edgesof the generally parallelly arranged first and second walls 522 and 523that jointly extend to the opposite side, wherein the second wall edges527 form a closed side for preventing an outgoing airflow; a partitionwall 530 lying between the first wall 522 and the second wall 523; afirst nozzle airflow outlet 528 a located between the first wall edge526 of the second wall 523 and the partition wall 530; a second nozzleairflow outlet 528 b located between the first wall edge 526 of thefirst wall 522 and the partition wall 530; and a diffusion surface 529for guiding an airflow in a predetermined direction. The first wall edge526 of the second wall 523 is folded in an annularly curved or bentmanner to form a first Coanda surface 534 a adjacent to the first nozzleairflow outlet 528 a and capable of producing the Coanda effect toincrease the overall flow rate of the output airflow. The partition wall530 between the first wall 522 and the second wall 523 is folded in anannularly curved or bent manner to form a second Coanda surface 534 badjacent to the second nozzle airflow outlet 528 b and capable ofproducing the Coanda effect. The diffusion surface 529 guides the outputairflow in the predetermined direction. In a preferred embodiment, thepartition wall 530 is folded either inward (i.e., in the oppositedirection of the airflow direction) or outward (i.e., in the airflowdirection) in an annularly curved or bent manner to form a closed wall,which in turn forms a plurality of second Coanda surfaces 534 b as wellas a plurality of second nozzle airflow outlets 528 b.

Please refer to FIG. 9 and FIG. 10 for a external perspective view and asectional view of the fourth embodiment of the present inventionrespectively.

As shown in FIG. 9 and FIG. 10, the fan 60 in the fourth embodiment ofthe present invention includes a base 61 and a plurality of nozzles 62.

The base 61 has: a plurality of internal fans 611 for taking in air andejecting airflows, wherein the internal fans 611 are planar fansconnected in series to each other; a base airflow inlet 612 for takingin air; and a base airflow outlet 613 for ejecting an airflow.

The nozzles 62 are mounted on the base 61. Most of the central portionof each nozzle 62 is hollow to allow passage of light and an airflow andto increase the range of airflow input. Each nozzle 62 has: a nozzleairflow inlet 621, which is an opening located at the nozzle 62 andconfigured for receiving the airflow ejected from the base airflowoutlet 613; a first wall 622; a second wall 623 arranged generallyparallel to the first wall 622, wherein in this embodiment, a secondwall end is joined with a first wall end to form an annular hollowportion that encircles the light- and airflow-penetrable central hollowportion of the nozzle; first wall edges 626, which are wall edges of thegenerally parallelly arranged first and second walls 622 and 623 thatjointly extend to one side; second wall edges 627, which are wall edgesof the generally parallelly arranged first and second walls 622 and 623that jointly extend to the opposite side, wherein the second wall edges627 form a closed side for preventing an outgoing airflow; a partitionwall 630 lying between the first wall 622 and the second wall 623; afirst nozzle airflow outlet 628 a located between the first wall edge626 of the second wall 623 and the partition wall 630; a second nozzleairflow outlet 628 b located between the first wall edge 626 of thefirst wall 622 and the partition wall 630; and a diffusion surface 629for guiding an airflow in a predetermined direction. The first wall edge626 of the second wall 623 is folded in an annularly curved or bentmanner to form a first Coanda surface 634 a adjacent to the first nozzleairflow outlet 628 a and capable of producing the Coanda effect toincrease the overall flow rate of the output airflow. The partition wall630 between the first wall 622 and the second wall 623 is folded eitherinward (i.e., in the opposite direction of the airflow direction) oroutward (i.e., in the airflow direction) in an annularly curved or bentmanner to form a closed wall, wherein the closed wall forms a secondCoanda surface 634 b adjacent to the second nozzle airflow outlet 628 band capable of producing the Coanda effect. The diffusion surface 629guides the output airflow in the predetermined direction.

FIG. 11 is a schematic view of an example of a forced-draft fan in thepresent invention. Configured to take in air and eject an airflow, theforced-draft fan 70 disclosed in FIG. 11 has a forced-draft fan airflowoutlet 71, a forced-draft fan airflow inlet 72, a forced-draft fan blade73, and a forced-draft fan motor 74.

FIG. 12 is a schematic view of an example of a planar fan in the presentinvention. Configured to take in air and eject an airflow, the planarfan 80 disclosed in FIG. 12 has a planar-fan airflow outlet 81, aplanar-fan airflow inlet 82, a planar-fan blade 83, and a planar-fanmotor 84.

FIG. 13 is a schematic view of an example of a jet turbine-blade fan inthe present invention. Configured to take in air and eject an airflow,the jet turbine-blade fan 90 disclosed in FIG. 13 has a jetturbine-blade fan airflow outlet 91, a jet turbine-blade fan airflowinlet 92, a jet turbine-blade fan blade 93, and a jet turbine-blade fanmotor 94.

According to the above, the present invention solves the problem that,if the areas of the nozzle openings of a bladeless fan with a Coandasurface are to remain unchanged, the Coanda surface cannot be enlargedwithout increasing the volume of the nozzle.

The present invention is such valuable in this field so that submit anapplication. While example embodiments have been disclosed herein, itshould be understood that other variations may be possible. Suchvariations are not to be regarded as a departure from the spirit andscope of example embodiments of the present application, and all suchmodifications as would be obvious to one skilled in the art are intendedto be included within the scope of the following claims.

What is claimed is:
 1. A fan, comprising: a base; and a nozzle mountedon the base and having: a nozzle airflow inlet located at the nozzle andconfigured as an opening for receiving an airflow ejected from the base;a first wall; a second wall arranged generally parallel to the firstwall; a first wall end located at an end of the generally parallellyarranged first and second walls; a second wall end located at anopposite end of the generally parallelly arranged first and secondwalls; first wall edges, which are wall edges of the generallyparallelly arranged first and second walls that jointly extend to aside; second wall edges, which are wall edges of the generallyparallelly arranged first and second walls that jointly extend to anopposite side; a partition wall located between the first wall and thesecond wall; a first nozzle airflow outlet located between the firstwall edge of the second wall and the partition wall and configured as anopening for ejecting an airflow; and a second nozzle airflow outletlocated between the first wall edge of the first wall and the partitionwall and configured as an opening for ejecting an airflow; wherein thefirst wall edge of the second wall is folded in an annularly curved orbent manner to form a first Coanda surface adjacent to the first nozzleairflow outlet and capable of producing the Coanda effect, and thepartition wall is folded either inward in an opposite direction of anairflow direction or outward in the airflow direction in an annularlycurved or bent manner to form a closed wall, the closed wall forming asecond Coanda surface adjacent to the second nozzle airflow outlet andcapable of producing the Coanda effect.
 2. The fan of claim 1, whereinthe second wall edges form a closed side for preventing an outgoingairflow or an opening that allows passage of an airflow.
 3. The fan ofclaim 1, wherein the second wall is folded inward in the oppositedirection of the airflow direction in an annularly curved or bent mannerto form a closed wall for preventing an ingoing airflow, or the secondwall is folded outward in the airflow direction in an annularly curvedor bent manner to form the first Coanda surface adjacent to the firstnozzle airflow outlet and capable of producing the Coanda effect.
 4. Thefan of claim 1, wherein the second wall end is joined with the firstwall end to form an annular hollow portion, and the annular hollowportion encircles a central hollow portion that allows passage of lightand an airflow.
 5. The fan of claim 1, wherein the second wall end has asecond tightly closing wall for preventing passage of an airflow, andthe first wall end has a first tightly closing wall for preventingpassage of an airflow.
 6. The fan of claim 1, wherein there is one saidnozzle airflow inlet, provided at the first wall or the second wall; orthere are a plurality of said nozzle airflow inlets, provided at thefirst wall or the second wall.
 7. The fan of claim 1, wherein the secondnozzle airflow outlet formed between the first wall edge of the firstwall and the partition wall is a tapered slit, and the first nozzleairflow outlet formed between the first wall edge of the second wall andthe partition wall is a tapered slit.
 8. The fan of claim 1, wherein thesecond nozzle airflow outlet formed between the first wall edge of thefirst wall and the partition wall is a rectangular slit, and the firstnozzle airflow outlet formed between the first wall edge of the secondwall and the partition wall is a rectangular slit.
 9. The fan of claim1, wherein the first nozzle airflow outlet or the second nozzle airflowoutlet is divided into a plurality of spaces by a plurality of partitionplates.
 10. The fan of claim 1, wherein there are a plurality of saidpartition walls so as to form a plurality of said second Coanda surfacesas well as a plurality of said second nozzle airflow outlets.
 11. Thefan of claim 1, wherein the second wall has a diffusion surface forguiding an airflow in a predetermined direction.
 12. The fan of claim 1,wherein the second wall edge of the first wall is folded in an annularlycurved or bent manner to form a third tightly closing wall, and thethird tightly closing wall is adhesively attached to the second wall toprevent an outgoing airflow.
 13. The fan of claim 1, wherein the secondwall edge of the second wall is folded in an annularly curved or bentmanner to form a third tightly closing wall, and the third tightlyclosing wall is adhesively attached to the first wall to prevent anoutgoing airflow.
 14. The fan of claim 1, wherein the nozzle includes athird tightly closing wall, and the third tightly closing wall has twosides adhesively attached to the first wall and the second wallrespectively to prevent an outgoing airflow.
 15. The fan of claim 1,wherein the base has an internal fan for taking in air and ejecting anairflow, a base airflow inlet for taking in air, and a base airflowoutlet for ejecting an airflow.
 16. The fan of claim 15, wherein theinternal fan is a forced-draft fan, a planar fan, or a jet turbine-bladefan.
 17. The fan of claim 15, wherein the internal fan is a plurality ofparallel-connected or series-connected planar fans.
 18. The fan of claim1, wherein the base comprises a filter screen provided therein.